Modelling Hydrological Consequences of Climate Change—Progress and Challenges

The simulation of hydrological consequences of climate change has received increasing attention fromthe hydrology and land-surface modelling communities. There have been many studies of climate-changeeffects on hydrology and water resources which usually consist of three steps: (1) use of general circulationmodels (GCMs) to provide future global climate scenarios under the effect of increasing greenhouse gases,(2) use of downscaling techniques (both nested regional climate models, RCMs, and statistical methods)for "downscaling" the GCM output to the scales compatible with hydrological models, and (3) use ofhydrologic models to simulate the effects of climate change on hydrological regimes at various scales.Great progress has been achieved in all three steps during the past few years, however, large uncertaintiesstill exist in every stage of such study. This paper first reviews the present achievements in this field andthen discusses the challenges for future studies of the hydrological impacts of climate change.